And what good does staying do? If we stay we're bad, awful imperialists and playing global police. If we leave we're bad too for letting Afghanistan return to the year 2000. If you're damned either way might as well save money. Maybe the EU can step up and commit resources and money and prevent this outcome you're describing. Why does America have to do it?
I think most Americans hold this viewpoint too. If you don't like it, I think it might be beneficial to go back and look at the years of "America in Afghanistan bad" international press. No wonder Americans said "fuck it we're done".
Funny enough the more controversial war (Iraq) seems to have brought about the more successful long-term change. U.S. forces are effectively out and the Iraqi government is running Iraq. Would be great if the Iranians would stop meddling but is what it is.
In what specific ways?
It's either that or don't go there in the first place. Afghanistan has been cynically used by world powers over and over again to get at each other and as a convenient battle field. Leaving it to the Taliban will only guarantee another chapter in that series.